Catalyst-Free Radical Carbosulfonylation of Enamides with Indoles, Aryldiazonium Tetrafluoroborates, and DABCO·(SO 2 ) 2 .

Herein, we have developed a catalyst-free four-component carbosulfonylation of enamides involving indoles, DABCO·(SO 2 ) 2 , and aryldiazonium tetrafluoroborates for the preparation of various β-amidosulfone products in moderate to excellent yields. This approach features mild reaction conditions, high step-efficiency, and broad substrate scope, which provides a green and efficient strategy for carbosulfonyl difunctionalization of enamides. Based on the results of mechanism studies, a radical tandem reaction process is proposed for the transformation.